Apparatus for mining roof-props



E. C. MORGAN.

APPARATUS FOR MINING ROOF PROPS.

APPLICATION FILED JULY 5. 1917.

Patented Feb. 10, 1920.

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E. c. MORGAN. APPARATUS FOR MINING ROOF PROPS.

' APPLICATION FILED JULY 5.1917- 1,330,743. Patented Feb. 10,1920.

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APPARATUS FOR MINDNG ROOF PROPS,

I917 Patented Feb. 10, 1920,

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E. C. MORGAN. APPARATUS/FOR MINING ROOF PROPS. APPLICATION man JULY5.1911;

1,330,743; Patented Feb. 10, 1920.

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APPARATUS FOR MINING ROOF PROPS.

APPLICATION FILED JULY 5.1911.

5 vwewto'c Edmund Ullozy m Hi i m EDMUND MORGAN, F NEW R arranaros FORMINING 'noor-rnors.

Original application filed Junev 7, 1912, Serial No. 762,373,

Specification of Letters Patent.

Patented Feb. 10, 1920'.

Divided andthis application filed July 5, 1917.

Serial No. 178,766.

county of Queens and State ofNew York,

haveinvcnted certain new and useful Improvements in Apparatus for MiningRoof- Props, of which the following is a specification.

The present application is adivision of my copending application SerialNo. 702,373, filed June 7, 19.12, for an improvement in a method ofmining.

My invention relates to apparatus for dislodging a mass of material fromits native bed in a mine chamber, and one of the objects of my inventionis the provision of apparatus for dislodging masses of material ofpredetermined shape and height so that theycan be used in a mine chamberas roof props.

More particularly itis the object of the present invention to providemechan sm for cutting lrerfs about a mass of material 111 the roof orfloor of a mine chamber to form a am of material which can easily be ncits-o as to have a height QPPI'OXlequal to the distance between theandroof of tie mine chamber, to permit the frustum to be used as aroof'prop spaced from the place of dislodgment.

(Ether objects of the invention will appear hereinafter, the novel.features and combinations of elements being set forth in the apbros.

. pended claims.

In the accompanying drawings Figure 1 is a plan view of a machine forcutting conical kerfs in the roof of a mine chamber Fig. 2 is a secional elevational view taken on the lines A-l3 and EF of Fig. 1;

Fig. 3, is a sectional elevational view on the line NO of Fig. 1 lookingin the direction of the arrow;

Fig. 4: is a plan view of a modified machine for cutting kerfs to formtapering sections or frustums of pyramids or of paralleiopipedons Fig. 5an elevational view of the kerfcutting mechanism used in the machineshown in plan in Fig. 4;;

Fig. 6 is an enlarged elevation of the cutters shown at the lower end ofFig. 4; Fig. 6 is also a view in elevation from the lefthand side ofFig. 5;

Figs. 7, 8, 9 and 10 illustrate diagrammatically the operation of thecutting mechanism shown in Figs. 4, 5, and 6;

Fig. 11 illustrates the application of the machineshown in Figs. 1 and 2to the roof of a mine chamber;

Fig. 12 illustrates a. method of dislodging frustums of cones from thehard floor of a mine chamber by means of a machine simi lar to thatshown in Figs. 1 and 2; v

Fig. 13, illustrates the method of using the machine shown in Figs. 1and 2 to dislodge a frustum-of a cone from the roof of an inclined minechamber;

F 14 illustrates a method of using-the machine shown in Figs. 1 and 2 toform a series of double arched supports between the floor and the roofof a mine chamber;

Figs. 15, 16 and 1? illustrate different shaped frustums which may bedislodged into a mine chamber and used as roof props therein;

Fig. 18illustrates diagrammatically mech anism for shifting thedislodged frustums to new locations in the mine chamber where they areto act as roof props, and also mechanism for lifting the floor frustumsinto the mine chamber, and mechanism for moving the kerf-cutting machineto new locations in the mine chamber.

Fig. 19 is a view similar to Fig. 18 but more complete F ig. .20 isanelevational view of the hoisting mechanism shown in Fig. 19;

Fig. 21 is an enlarged View showing the mechanism for connecting a draftrope to a tapered section of dislodged material;

Fig. 2:2 is a sectional elevation of the pumping mechanism for operatingone of the lifting arms; and

Fig. 23 is an enlarged sectional elevation of the right hand portion ofFig. 2 but more clearly illustrating one of the individual drillingmachines.

Coal mining in many sections is carried on very ineliiciently becauseonly the best coal and that most easily removed is usually mined. Themethods of mining usually pursued result in the distortion and ruin ofveins of coal above the places where mining operations are being carriedon and also the loss of much of the coal in the vein being worked. Apreferable method of mining is by the long wall system by which all ofthe mineral is removed as the mining progresses, but owing to thediffiwhy and expense of holding up the roof only a small percentage ofcoal mining in this country is carried on by that system, and even whereit is practicable it often has the objection of disturbing the veins ofmineral in overlying strata and of disturbing the land at the surface,tending to render it useless for farming purposes.-

Owing to the difficulty of holding up the roof nearly all of the coalmining in this country is now carried on by what is known as the roomand pillar system, which, in most cases, is very wasteful of the coal inthe vein being worked, destructive to the veins in the overlying strataand to the land at the surface; in addition, a large amount of timberingis required to support the roof of the mine chamber a suflicient lengthof time to enable the mining of the coal therein. In the aggregate avast forest of timber is disappearing into the mines yearly andfurthermore the fatalities which occur every year by reason of fallsfrom the breaking roofs, are more than from all the other causescombined, even including the terrible gas and dust explosions that occurfrom time to time.

By the use of my methods of supporting mine roofs hereinafter describedand disclosed in the drawings, which methods can be carried on inlow-roofed mine chambers as well as high-roofed mine chambers,practically all of the mineral is saved in the vein being worked, andnone of the mineral in the strata above or the land at the surface, isdisturbed. These methods also enable the mining to be carried on with amuch greater degree of safety to the operatives than with the methodsheretofore usually carried out. These methods arev de scribed andclaimed in my copending applications. Ser. Nos. 187 ,7 03 and 198,746,respectively filed August 22, 1917, and October 26, 1917 both formethods of mining.

Inasmuch as one of the most important problems in metal mining as wellas in coal mining, is holding up the roof while the mineral is beingremoved, I wish it to be understood that the apparatus herein describedmay have a general application for mining purposes.

The strata immediately overlying a coal vein is usually slate orsandstone which is harder and more capable of sustaining great weightthan the strata immediately under lying the vein of coal, whichunderlying strata is usually fire clay or shale. Sometimes, however, theconditions stated are reversed and the mine chamber will have. asandstone or limestone floor and a comparatively soft roof.

My improved method of supporting mine roofs as covered in the aforesaidco-pending applications, consists in removing wedge,

cone or pyramid shaped sections in one piece from either the roof or thefloor, of a height approximately the same as the distance between thefloor and the roof of the mine chamber, and placing them at pointsadjacent to where the sections have been removed. The shape of thesections may be predetermined and also their height before beingdislodged from the mass of unmined material. The height of each sectionmay be made suiiiciently less than the height between the floor and theroof to permit the sections to be moved freely to the point desired,making allowance for unevenness of the floor and roof. Ordinarily thisis all that will be required owing to the shape of the sections. Theirheight can be determined before removal so that they will be practicallytight when shifted into the desired positions. Slight settling of theroof may then be relied upon to form a firm bearing without causing anycracking of the roof or any appreciable disturbance above the minechamber. However, if desired, it is entirely practicable to drive thinwedges in the slight clearance space so that heavy pressure maybeapplied between the fioor and the roof against each section as soon asanchored in the desired position. It should be understood that theoperator can determine just where he wants to place the section beforehe removes it, and, with suitable extensible measuring means, can decidejust what height he wants the section to be, andowing to the wedgelikeshape of each section, it can be broken off at almost exactly apredetermined point.

The number of sections necessary to be used for a given area will ofcourse vary greatly owing to the character and weight of the overlyingstrata of material, the character of the material from which thesections are taken, the character of the material of the floor, etc.,but it can all be predetermined with accuracy by those skilled in theart. Preferably sufficient sections should be used to hold the roof upindefinitely, so that it may be practicable to work, at any time in thefuture, the coal veins that may be in the overlying strata.

Referring to the drawings, Fig. 11 is a sectional view through a coalmine, including part of the roof and floor. In this case the roof iscomposed of much stronger material than the floor and therefore the propsections are taken from the roof. The coneshaped section 25 is shownready to be removed to a position similar to the section 26 which hasbeen placed in its permanent position. Ordinarily a section such as thatdesignated 25 will break away from the unmined mass at the line 27 owingto thefact that it is the smallest and weakest cross-section. If in somematerial the conical sec tion which is that designated 25, is not brokenoff of its own weight, a wedge or similar means may be used to :assistin breaking the conical section along the line 2?. Thin wedges 28 and 29may be used, if desired, between the roof and the upper end of theconical section after the latter has been moved to the position where itis to be located permanently, but the space that need be left betweenthe top of such a section as that designated 26 in Fig. 11, and theroof, may be much less in proportion than that shown in the drawings, inwhich the size of the wedges 28 and 29 is exaggerated for clearness inillustration.

When a section has been dislodged from the roof I prefer to let it-downslowly, but it may be allowed to drop quickly if desired, particularlywhere the base is rather large and the air under the same will act as acushion. After a section such as that designated 25 in Fig. 11 has beenlowered to the floor, it may be moved by any simple means, such as awinding engine of ordinary and well-known construction, asdiagrammatically illustrated in Fig. 18.

In many mines none of the usual props need be regularly used, althoughif desired such props as those indicated at 81 may be used withoutinterfering with the application of my invention.

In Fig. 12, which is a cross-section through a coal mine chamber havinga hard floor and a comparatively soft roof, I have shown the sectionsbeing taken from the hard floor. Near an ordinary prop 1% a section hasbeen cut and wedge 42 may be used to break off the section along-theline 18. The sections taken from the hard floor are lifted from the minechamber and moved over to a permanent position such as. the sectiondesignated 11, which may be securely anchored in 'positionby means ofthe wedges 45 and 46.

In Fig. 13 I have shown my method applied to a very steep pitchingveinin which 4:? indicates a coneshaped section before removal. from theroof and 48 indicates a section in permanent position. Thin wedges 19and 50 may be used for locking the sec tion 4:8 in place. In this casethe sections, after removal, may be guided to the desired permanentposition, by their own weight which will cause them to slide over thefloor of the mine chamber.

Fig. 18 is a plan view showing diagrammatically a convenient arrangementfor moving the dislodged sections into place after they have beenlowered to the floor; also for lifting and placing the sections as theyare taken from the floor; and also for moving the cutting apparatus tonew locations in the mine chamber. On a suitable frame 53 is mounted arope-winding drum 51 operated by an electric motor 52. The frame mayslide on the floor of the mine and be anchored in any suitable way, asby means of the anchor 54. A boom 55 and sling rope 56 may be mounted onthe frame 53, as shown in Fig. 18, and arranged to be operated by therope 57, winding drum 51, the motor 52 and the intermediate mecha nismbetween the winding drum and the motor. By referring to Fig. 12 it willbe seen that the sling rope 56 may be placed around the lOWer portion ofthe section 10 and when the winding mechanism is oper ated the boom 55may be lifted to hoist the section 10 out of the floor, and the boom 55may then be swung around on its pivotal connection'with the frame 53 toplace the section in the position shown at 4.1 in Fig. 12.

Referring again to Fig. 18, it will be seen that the rope 57 is carriedaround the pulley 58 which is connected to anchor at 59. The rope 57then extends around the pulley 60 which may be anchored by the conicalprop section 61 which is already in permanent position in the minechamber, or such pulleys 60 may be anchored by any other suitable means.The end of the rope 57 may be formed into a loop 57 and placed arountthe section 63 which to be moved. Suit able clamps 64, 65 and 66 may beattached to the rope 57. These clamps may be hoo ishaped at one end toengage the lower edge of the section 58 andprevent the rope pulling tothe top of the section. It should be noted that the pulley 60 isconnected to the permanently located section 61 by means of a loop 60and hooks similar to those designated 6%, 65 and 66. It should also benoted that when the sections 61 and 63 are permanently anchored in themine chamber, or when the pulley 60 is connected to an anchor in a mine,and the end of the rope 57 is also anchored, and the anchor 54: isreleased, the operation of the winding mechanism may then be relied uponto shift the frame 53 and the parts thereon to a new location in themine chamber. It should also be noted that as indicated by the dottedlines in the central portion of Fig. 18, the rope 57 may be connected tothe frame 6'? of the cutting apparatus hereinafter described, to shiftthe latter about in the mine chamber. It should also be noted that theapparatus diagrammatically illustrated in Fig. 18 may be employed formoving sections over the mine floor so long as said sections will restflatly thereon. This is accomplished with facility with such taperingsections as shown in Figs. 15,16 and 17 in which the flat bases are muchlarger than the upper surfaces. However, the mechanism shown at thelefthand portion of Fig. 18 may also be used to move inverted sectionsbecause the larger bases will then be at the roof and on account oftheirheights being approximately equal to the distance between the floor andthe roof, such sections will not tip over, and

moreover the hook clamps will remain connected to the circumferentialedges of the tops at the roof.

Fig. 1 1 is a diagrammatic view of a mine chamber Showing a number ofsections in place. It will be noted that the air spaces left between thesections are diamond-shaped and therefore arch upwardly and downwardly;this would be the case whether the sections were taken from the roof orfrom the floor, thus in either case forming a structure of greatstrength to resist immense crushing strain from above.

I will now describe the preferred apparatus for removing cone-shapedsections from the roof or from the floor of the mine chamber. ComparingFigs. 1 and 2 it will be seen that the latter and its left-hand portionor that bounded by the lines G, H, I, J, is a sectional elevation ofFig. 1 on the line AB looking in the direction of the arrow; while theright-hand portion of Fig. 2, or that portion bounded by the lines H, I,L, K, is a sectional elevation on the line EF of Fig. 1 looking in thedirection of the arrow; while that part bounded by the lines K, L, M ofFig. 2 is a sectional view on the line CD of Fig. 2 looking in taedirection of the arrow. Fig. 2 therefore brings into elevation some ofthe essential features of Fig. 1. Fig. 3 is a sectional elevation on theline NO of Fig. 1, looking in the direction of the arrow.

The main frame 75 of Figs. 1, 2 and 3 is in the general form of athree-quarter segment of a circle. Rotatably mounted in the main frame 75 by means of a suitable grooved bearing is the frame 76, which is alsoin the general form of the shape of about a three-quarter segment of acircle, and has suitable gear teeth 171 formed on its outer periphery.Arranged to mesh with the gear teeth 171 on the frame 7 6, are thepinions 77 and 7 8 which are secured to the shafts 79 and 80 carried insuitable bearings in the main frame 7 Secured to the shafts 79 and 80are worm gears 81 and 82 which mesh with worms 83 and 84:, the latterbeing suitably secured to the shaft 85 which is mounted in bearings 86and 87 extending from the main frame 75. An electric motor 88 mounted onthe frame 75 is connected to the shaft 85 through the gears 89 and 90.

()n the frame 76 is mounted the standard 91 for supporting areciprocating tool which may be of well-known construction, the oneillustrated being operated by electric power. This reciprocating toolcomprises a frame 93 on which the frame of the cutting tool is slidablymounted for feeding movement either by hand or power. The frame 93 isprovided with a lateral extension 94 which is arranged for universaladjustment by means of suitable clamps connected between the extension 91 and the supporting standard 91, as indicated at 95. There may be aplurality of such reciprocating tools carried by the frame 75. Forinstance, another reciprocating tool may be mounted on the standard 96which is similar to the standard 91. Electric current is arranged to becontinuously supplied to the reciproeating tool by means of a suitableflexible connecting insulated Wire 97. This wire is electricallyconnected to a suitable conducting strip 98 which is mounted on theperipheral portion of the frame 76, suitable insulation intervening andextending around the frame 76 over nearly its entire length. One of thewires from the source of power may be connected to the brush 99 which ismounted on the frame 75 and insulated therefrom but in elctrical contactwith the metal ring 98, which metal ring is electrically connected bythe insulated wire 97 to the motor on the reciprocating tool. The otherterminal of the motor may be grounded on the frame 76 and a brush 100mounted on the frame 75 at 102 allowed to come in contact with the frame76. The brush 100 is insulated from the frame 75, however. It willtherefore be evident that a plurality of electric motors may beconnected in parallel between the source of power connected to themachine at the points 101 and 102.

One of the important features of my invention is the apparatus forletting a sec tion down to the floor slowly to the dotted line positionshown in Fig. 2 so that it will remain intact. Mounted on the frame 75by means of suitable bearings 103, 10 1, 105 and 106, as shown in Fig.1,are the crank shafts 107 and 108, at the outer ends of which aresecured arms 109, 110, 111 and 112, the free outer ends of which carryrollers 118, 114:, 115 and 116 by means of suitable bearings andjournals.

Each pair of arms 109, 110 and 111, 112 is operated and controlled bysimilar mechanism illustrated at the left-hand portion of Fig. 2.Preferably hydraulic power is used, although the mechanism may beoperated by a gaseousmedium instead of a liquid medium. The frameworkcontaining the hydraulic operating cylinder pump and valves, is showncast integrally with the frame 75. A plunger 117 in the operatingcylinder is connected at its upper end to the crank shaft 108 by meansof the connecting rod 118. The pump plunger 119 is operated by aneccentric cam 120 which is secured to the vertical shaft 121. To theupper end of the latter is secured a gear wheel 122 which meshes withand is driven by the gear teeth 171 on the frame 7 6. The usual pumpvalves are indicated at 123 and 12 1. The valve 125 controls themovement of fluid to and. from the plunger cylinder, holding the plungeror releasing it as may be desired. I wish it to/be understood that Ihave shown only the simplest operating apparatus for effecting movementof the pairs of arms so as to simplify the draw ings. Self-containedhydraulic pumps including plungers, valves, etc. sold on the market, maybe readily applied without departing from the, spirit and scope of myinvention. Y

The operation of the pumping apparatus for actuating the pairs of arms,is as follows: The. apparatus being placed in proper position, power isapplied to the arms 109,110, 111 and 112,.forcing them up tightlyagainst the roof, serving the double purpose of supporting the sectionto be cut and anchoring the apparatus against vibration during thecutting operations. The channelling tools arethen started and the frame76. rotated by feeding the same around. the frame 75. This isaccomplished by starting the electric motor 88' which ef fectsturning ofthe gears 81 and82. each in the same direction, and therefore transmitsrotative power through. the pinions 77 and 78 to the large gear 171 andcauses the frame 76, together with the cutting tools mountedthereon, tomove in an are on the frame 75. which is held stationary. This action offeeding the. channeling tools in a circular direction willresult in thecutting out of the material. from the roof of apractically perfectconeshaped section, and by means of the adjustments shown any angle ofcone desired may be obtained, and by means of suitable gages thevfeeding of the channeling tools may be stopped.

It should be understoodthat the motor 88 may be operatedso as tosecurea:continuous rotary feed. of the supplemental cutting frame always inthe same direction, if so desired. That isto say, the supplementalcutting frame may be rotated indefinitely about the main frame 75constantly in the same direction through complete rotations. This isdesirable when there is .a smallnum her of cutters, and enables a singlecutterto cut a cone. In such event, however, the electric brushes 99vand 100 should each contact with the slip ring 98 and the same. mainlead from thesource of power connectedrto both the points 101 and 102,the motor for the cutter being then groundedonthe main frame, andtheother leadfromthe source of power connectedto such main frame. Thenthere would be always an electrical circuit through the electric motorof; the cutting tool, although at intervals the brushes 99 and 100 wouldrun off the slip ring on account. of the opening in the, frame 7 6.

When the desired section of the conehas been out, the pressure on the.pairs of arms 10,9, 110 and 111,. 112.. can then be eased, which willordinarily result in the section being severed by its own weight at theweakest point which is the cross-section at its upper end, as indicatedat 27 in Fig; 11. If in some material the breaking did not occur by theweight of the cone, a heavy breaking strain can be applied by releasingone pair of arms slightly and putting further pressure on the other pairof arms. If still further pressure is desired, a wedge can be applied inthe channel or conical kerf at the side next to the released arms, andpower can even be applied to this wedge by pulling a blunt tool on oneof the channeling plungers and causing the latter to strike the wedge.

The pumping apparatus may be so arranged that when the valve 125 isclosed and the pump operated, the pressure medium will be forced intothecylinder below the plunger 117 past the check valve 124. Afterthepump is connected to operate continuously or intermittently, thevalve 125 may be opened sufliciently to cause a circulation withoutminimizing the pressure-on the plunger 1'17 and thereby regulating theforce with which the pairs of arms are held up; As soon as the sectionis severed, however, the regulating valve 125 may be opened wider by theoperator and the section will drop to thefioor at a speed correspondingto the degree to which the valve 125 is opened. After the rotation ofthe cutting apparatus is stopped, the valve 124 may keep the fluid fromescaping from the cylinder below the plunger 117, and if the valve 125is entirely closed the arms may be held up, but if' the valve 125 isopened the plunger 117 will descend and so also the pairs of arms. Thediameter of the interior of the frame 75 may be such as compared withthelength of the pairs of.arms, that the arms will be free to bemovedupwardly again after the section has been lowered to the floor, asshown-in Fig. 2. The dotted arc shows the path of movement of the roller113 in Fig. 2 and there is also shownin dotted lines at the left-handportion of Fig. 2, the vertical position of the arm 109. VVhentheconical section has been lowered to the floor, as indicated-by thedotted lines in Fig. 9, the apparatus-may bemoved to a new location.Inasmuch as the frames 7 5 and 76 are each provided with gaps which mayregister with each other when placed in proper relation, an'opening isprovided for the'whole apparatus to slidepast the conical section. Thisis illustrateddiagrammatically in Fig. 18 by the segment of a ringdesignated=67. A convenient hook, as that designated 128 in Fig. 1, maybe located onthe frame 75- diametrically opposite the segmental openingin the frame 75, so that the; hoisting rope'57 may be hitchedthereto asillustrated diagrammatically in Fig. 18,, or other suitablepulling meansmay beconnected to the hook 128 to withdraw the cutr al ting apparatusfrom the conical section which has been carved out from the roof anddislodged to the floor of the mine chamber. I wish to call particularattention to the fact that sometimes the roofs or floors of minesconsist of material which, while strong, such as some slates, may stillbe most rapidly cut by rotary cutters, in which case some simple form ofcutting tools, well known to those skilled in the art, may be applied inplace of the percussion cutters shown in Figs. land 2, and properfeeding mechanism similar to that shown in Figs. 1 and 2, may be used torotate the frame 76 to produce the same shaped section as that formed bythe cutters shown in Figs. 1 and 2.

In Figs. 4, 5 and 6 are shown modifications for mounting cuttingapparatus to enable it to cut wedge or pyramid shaped sections from theroof of the mine or from the floor, by a simple modification. 130 and131 indicate suitable drill or percussion tool frames on which aremounted tool apparatus operated either by compressed air orelectrically, and each of which may be of wellknown construction so thatdetailed description is deemed unnecessary. The drill frame 130 by meansof a bracket 132 is pivoted to the frame 133 as shown in Figs. 5 and 6.The bracket 132 is pivoted to the frame 133 by means of a suitable pin134, as shown in Fig. 5, and the frame 133 is pivoted on the frame 135by means of a suitable pin 136, as shown in Fig. 6. The pins 134 and 136are located at right angles to each other and the connections are suchas to mount the cutting mechanism for universal movement on the frame135.

An arcuate bracket 146 concentric with the pin 136 is rigidly attachedto the frame 133 and slides through a lug 147 which is rigidly securedto the frame 135. By means of set screw 148 the bracket 146 may besecured to the lug 147 so as to hold the frame 133 secured to the frame135 in definite relation thereto. This cutting apparatus mounted on theframe 135 is complete and self-contained and will operate in anyposition in which it is placed.

Mounted on the frame 133 is a motor 137 the framework of which by meansof suitable brackets carries a crank shaft 200 which is provided withsuitable bearings in the brackets. Secured to the crank shaft 200 is aworm gear 201 which meshes with and is driven by a worm 140, as shown inFig. 5, said worm 140 being secured to the motor shaft 141. Pivotallyattached to the drill frame 130 by means of a pin 142, is a bracket 143provided with a bearing to re ceive the connecting rod 144 which isconnected to the crank shaft 138. The connecting rod 144 is slidablyadjustable in the bracket 143 and can be held rigidly where desired bymeans of a suitable set screw 145. By means of this mechanism the frame133 may be oscillated to cause the reciprocating cutting tool to be fedback and forth at right angles to the direction of the cut into the bodyof the material from which the cone-shaped section is dislodged.

The drill bracket 131, shown at the lefthand portion of Fig. 6, ispivotally mounted in the frame 149 by means of a suitable bracket 150and pin 151 as shown in Fig. 4. A bracket 152 concentric with the pin151 is attached to the drill frame 131 and slides through a lug 1.53 onthe frame 149. A set screw 154 holds the bracket 152 in such a positionas desired in the lug 153. This ad justment is similar to that effectedby the arc-shaped bracket 146 shown at the righthand portion of Fig. 6.

The frame 149 is slidably mounted on a rack bar 155. The frame 149 bymeans of a suitable bearing and a shaft 157, carries a rack pinion 158.The pinion 158 is secured to the shaft 157 and meshes with the rack bar155. The rack pinion 158 may be suitably driven to feed the frame 149along the rack bar by means of the feed mechanism of the drill. Thedrill mechanism is of the rotary type in that it is provided withmechanism for rotating the drill and also the shaft 159. A suitableextension shaft 160 provided with universal joints and an intermediatesliding connection serves to connect the drill feed to the pinion 158.The bar 155 may be made as wide as desired to assure operative anglesfor the universal joints. It should also be noted that intermediate theextensible shaft 160 and the shaft 139 is a crank connected to mechanismfor automatically feeding the rotary drill mechanism along the frame131. The grooved shaft 139 is provided with a worm wheel which iscontinuously in mesh with a worm operated by the motor which rotates thedrill. It will thus be seen that the rotary drill is provided with meansfor automatically feeding it into the material and also along the kerfwhich it is making.

-The rack bar 155 may be supported at one end by a frame 161 throughwhich it is slidable in a slot and can be held at any point desired bythe set screw 163. The other end of the rack bar is carried by the bracebar 170 which has a slot therein to receive the end of the bar 155.Intermediate its ends the rack bar 155 is supported by' the frame 135 byextending through a slot in the latter. The frame 135 is somewhatsimilar to the frame 161 except that the frame 161 has two slots atright angles to each other, one for receiving the rack bar 155 and theother for receiving the longitudinal brace bar 162. The latter may besecured to the frame 161 by means of the set screw 164.

The longitudinal brace bar 162 is also supportedv by the frame 165 whichis a duplicate of the frame 161, exceptthatit is opposite-handed. Placedparallel to the rack bar 1 55.i's an additional rack bar 166 with itsrack teeth extending in the opposite direction. Oneend of'the rack bar166 rests in the frame 165 and the other end is extended through a slotin the brace bar 170. Intermediate its ends the rack bar 166 is supported by the frame 167 which is a duplicate of the frame 135eX-cept thatthe bracket or lug 168 which corresponds to the bracket 14? on the frame135, is opposite-handed. Therack bar 166 carries a frame 169 which is aduplicate of the frame 149 on the rack bar 155.

It: will be seen that the two rack bars 155 and 166 together with theplain bar 162 and the brace bar 170 thus form an adjustable framerectangular orsquare according to the degree of adjustment, and thatprovision is'mad'e for several drilling or channeling mechanisms eachadjustable from a vertical cutting position to any angular cuttingposition desired. Feeding mechanism is also provided for efiecting thecutting of a kerf of any desireddepth in the roof of the mine chamber.

Figs. 7, 8, 9 and 10 are diagrammatic illustrations showing the methodsof cutting which can be carried out by means of the apparatus shown inFigs. 4, 5 and 6.

Figs. 7 and 8 illustrate pyramid cutting while Figs. 9 and 10 illustratethe cutting of wedge-shaped sections. It should be noted that Fig. 8represents a side diagrammatic VlGW of Fig. 7 and that Fig. 10'is a sidediagrammatic view of Fig. 9. For instance, in Fig. 10 the left-hand kerfmay be cut by the two cutters shown in the lower port-ion of Fig. at andthe right-hand kerf of Fig. 10 may be cut. by the cutters the framesofwhich are shown in the upper portion of Fig. a; then by hooking thepulling apparatus shown in Fig. 18 tothe perforated plate 172, theentire apparatus shown in Fig. 4- may be shifted to such a positionbeneath the kerfs shown in F ig. 10 that the rack bars 155 and 166 maybe adjusted along the bars 162 and 170 so that the cutters on the rackbars may be operated and fed along the same to cut the diagonal kerfsshown in F 19. If'desired, however, the entire apparatus shown in Fig.1: may be left. in the'position therein shown after the vertical kerfsshown in Fig. 10 have been made. After the cutters are mounted on theframes 161 and 165, and the bars 155 and '166 shifted along the bar 162for. new locations of operation, of the cutters on the frames 161 and165, the ker-fs shown in Fig. 9 may thus be cut.

The brace bar 170 is inaderemovable so that when a section 1781 has-beendislodged it may be pulled out of the frame comprising the bars 155 and162 and 166 or such frame may be pulled away from the tapering section178.

I wish it understood that the mechanism shown in Figs. 1 and 2 forholding, breaking and lowering the cone-shaped sections may also be usedwith the apparatus shown in Fig. 1 for holding, breaking and'loweringthe wedge or pyramid-shaped sections. In some instances the cuttersthemselves may be used to support the block of coal and let it down tothe floor without breaking the dislodged section. It can readily be seenby referring to Fig. 5 that the cutter could be withdrawn from the kerfand the apparatus adjusted so as to project the cutter or aspecial toolsubstituted therefor under the body of the cut section before the latteris broken away from the unmined mass by projecting wedges into thekerfs. cutting devices at each end of the rectangular frame shown inFig. 4; would be sufli- Two l cient to lower a section of materialhaving a rectangular base.

If it is desired to out conical sections in the floor of the minechamber by means of the apparatus shown in Figs. 1 and 2, the brackets96 and 91 are bent into the angular positions shown at 126 and 127 inFig. 2. The cutting tools may then be directed downwardly and thefeeding apparatus operated'as before, and when such floor sections areto be removed they are dislodged by means of wedges and lifted to properposition by the mechanism diagrammatically illustrated in F 18.

Tapering sections may also be cut in the floor of the mine chamber bymeans of the mechanism shown in Figs. 4, 5 and 6. The cutting tools aremerely put on the lower sides of the rack bars instead of the uppersides and the frame suitably held in place by ceiling acks in a wellknown manner.

By referring to F ig. 1 of the drawings it will be seen that the bracket172 is extended laterally from the frame 92 for holding a cutter carrier178 having a cutter 174 at the upper end thereof. While in someinstances it may be preferred to employ mechanism for reciprocating thelarger cutting tool 175, it should be understood that such cutting toolmaybe held rigidly against reciprocation while the rotary feed takesplace. The conical feed toward the apex may or may not progress as thecutter is rotated. That is to say, the cutters 175 may make a completerotation and then be fed to a new cutting position, or the cutters maybe fed toward the apex very slowly while the same are being rotated. Thecutters 175 may be operated to a certain depth, and near the apex of thecone of material being cut, the cutters 17 1 may be brought into play.-Theccutters 17 1 are preferably turned in the opposite direction fromthe cutters 17 5 sothat when the feed is reversed or floor of the minechamber.

the cutters 17a may occupy an approximately radial position and be fedcloser to the apex of the cone. The carriers 173 are adjustably held inthe brackets 172, and after the cutters 175 have been operated to theirlimits. the cutters 17 4 may be extended by moving the carriers 173radially so that additional cuts may be made near the apex of the coneto facilitate the breaking away of the cone of its. own weight, thussaving the time of breaking away of the cone by means of manuallyoperated wedges.

It should also be noted that the rotary frame for carrying the cuttingmechanism is such that it may be held stationary wherever desired anddrills located in the bracket arms 91 and 96 so that holes may bedrilled, several at a time if desired, into the roof The drills may berelocated in various positions until a sufficient number of holesextending toward the apex of the cone have been drilled to enableblasting charges placed near the apex to dislodge a conical mass ofmaterial along the series of drill holes extending around such massapproximately in the shape of a cone.

It should also be noted that additional terminals 17 6 and 177 may beprovided on the main frame for connections from independent sources ofelectric power so that the electric motors for the drills or cuttingtools may be operated independently of each other. If desired, theterminals 101 and 102 may be connected to one of the mains extendingfrom the source of supply of elec tricity and the terminals 176 and 17 7connected to the other main, thus making terminals 17 6 and 177 theframe ground returns.

Obviously those skilled in the art may make various changes in thedetails and arrangement of parts without departing from the spirit andscope of my invention as defined by the claims hereto appended. I wish,therefore, not to be restricted to the exact structure herein shown anddescribed, but having shown the nature of my invention, and thepreferred embodiment thereof, what 1 claim as new and my own invention,and desire to have secured by Letters Patent of the United States, is:

1. In apparatus for forming props in mine chambers, the combination witha supporting frame, of cutters mounted on said frame in position tooperate upwardly therefrom, and means for operating said cuttersincluding the feed thereof to cut a tapering section of material fromthe roof of the mine chamber and above said frame.

2. In apparatus for forming props in a mine chamber from either the roofor the floor of the mine, the combination with a supporting frameadapted to rest on the floor of the mine chamber, of cutters mounted onsaid frame to project upwardly when in one position and downwardly whenm another position, and means for operatlng said cutters to form thefaces of tapering shaped sections from the roof of the mine chamber whensuch cutters are projected upwardly and from the floor of said minechamber when said cutters are projected downwardly.

3. Apparatus for forming cone-shaped sections out of solid material inits native bed in a mine, comprising a supporting frame, of cuttersmounted on said frame for movement relatively thereto circularly inhorizontal planes while said cutters extend upwardly from said frame,and means for operating said cutters to cause the same to form thecone-faces of said cone-shaped sections from such native bed above saidframe.

1. Apparatus for forming taperingshaped sections out of solid materialin its native bed in a mine, comprising a supporting frame adapted torest on the fioor of a mine chamber, cutters mounted on said frame toextend upwardly therefrom, and means for operating said cuttersincluding the feed thereof forwardly and laterally to describe a pathconforming to the sides of said tapering-shaped sections from the mineroof above said frame.

5-. Apparatus for forming tapering shaped-sections out of the solidmaterial of the. floor or roof of a mine, comprising a supporting frameadapted to rest on the floor of the mine chamber, cutters mounted onsaid frame in position to extend upwardly therefrom and in position toextend downwardly therefrom, and means for operating said cuttersincluding simultaneous feeding thereof forwardly and laterally into thematerial to cause them to describe a path conforming to the shape ofsaid tapering shaped sections to effect the dislodgment of the latterfrom the roof when said cutters extend upwardly and to effect thecutting of such sections when said outters extend downwardly relativelyto said frame.

6. Apparatus comprising a supporting frame havlng mechanism mountedthereon for forming a section from solid material in its native bed in amine chamber, and means mounted on said frame in position for engagingthe material to hold the same in place during the operation of saidcutting mechanism and until in readiness to be dislodged.

7. In apparatus for mining roof props, the combination with a supportingframe, of cutting mechanism mounted thereon, meansfor operating saidcutting mechanism to cut out from the roof of a mine chamber a sectionof material adapted to act as a roof prop between the floor and roof ofthe mine chamber, and means mounted on said frame in position to holdthe section of material in place during the operation of said cuttingmechanism and until in readiness to be dislodged.

8. in a mining machine, the combination with a supporting frame, ofapparatus mounted thereon for blocking out a section of material in itsnative bed in a mine, of means mounted on said frame for holding suchblocked out section in place until dislodged, and mechanism mounted onsaid framein position for effecting the placing of said section on thefloor of the mine chamber directly from its original. native position.

9. In a mining machine, the combination with a supporting frame, ofapparatus mounted thereon for dislodging a block of material from theroof of a mine chamber, and power mechanism mounted onsaid frame forhandlin said block of material.

after dislodgment.

10. Apparatus for forming cone-shaped sections of material from thefloor or roof of a mine, comprising a supporting frame adapted to reston the floor of a mine cham ber, a supplemental frame mounted on saidsupporting frame for rotary movement rel atively thereto, cuttersmounted on s id suppleniental frame to extend upwardly therefrom ordownwardly therefrom, means for operating said cutters including feedthereof forwardly into the material to cut a coneshaped section from theroof when said cut ters extend upwardly and to cut a coneshaped sectionfrom the iioor when said cutters extend downwardly, and means forrotating said frame together with the cutters n'ionnted thereon.

11. Apparatus for forming cone-shaped sections from the roof or floor ofa mine, comprising a main supporting frame adaped to rest on the floorof mine chamber, a iplemental frame rotatably mounted on said mainframe, means for rotating said supplemental frame on said main frame,cutters mounted on said supplemental frame 0 extend upwardly in positionto cut a t cone-shaped section from the roof or to eX- tend downwardlyin position to cut a coneshaped section from the floor, and means foroperating said cutters including the forward feed thereof.

12. Apparatus for blocking out sections from the floor or roof of a mineto form roof props, comprising cutters, means for operating said cuttersincluding the feed thereof, and mechanism comprising power-actuated andcontrolled arms for supporting, lifting and lowering the blocked outsections.

13. In a machine for mining roof props, the combination with asupporting frame, of cutting mechanism mounted on said frame, inposition to cut into the roof of a mine chamber or in position to cutinto the floor thereof, and means for operating said cutting mechanismincluding feed thereof to effect the dislodgment of roof props eitherfrom the roof or the floor of said mine chamber.

, 14. In a machine for mining roof props, the combination with asupporting frame, of cutting mechanism adapted to be mounted on saidframe either in position to cut into the roof or in position to cut intothe floor of the mine, and means for operating said cutting mechanismincluding the feed thereof to block out tapering sections from the floorand the roof of the mine chamber.

15. Apparatus for blocking out sections of material from the roof of amine chamber, comprising an open frame affording free passage of thesection of material from the roof to the floor of the mine chamber,cutters mounted on said frame, means for feeding saidcutters into thematerial in a direction in alinement with said cutters, means forfeeding said cutters substantially at right angles to the first namedfeeding direction, and mechanism for actuating said cutters during thefeed thereof into the material and along the same.

16. In mining apparatus, the combination with a supporting frame havinga free and unobstructed opening therethrough for the passage of asection of material from the roof of the mine chamber to the floorthereof, of cutting mechanism mounted on said frame in position to cut asection having a diameter nearly equal to the diameter of the saidopening, and means for operating said cutting mechanism to effect thecutting of a mass of material from the roof and the dis-- lodgmentthereof by its own weight after at taining a height approximately equalto the distance between the floor and roof.

17. In mining apparatus, the combination With a supporting frame havingan unobstructed opening therethrough for the passage of the section ofmaterial from the roof of the mine chamber to the floor thereof, of kerfcutting mechanism mounted on said frame, and means for operating saidkerf cutting mechanism into the roof above said frame until the massbounded by the kerfs is dislodged by gravity through said unobstructedopening to the floor of the mine chamber.

18. In mining apparatus, the combination with a supporting frame adaptedto rest on the floor of a mine chamber and having an unobstructedcircular opening extending vertically therethrough for the passage'of amine roof section having a circular bottom, a ring rotatably mounted onsaid frame, cutting mechanism mounted on said ring and extendingupwardly therefrom in an insaid circular opening, and means foroperating said cutting mechanism lncluding rota- ,clined position towardthe vertical axis of Y tion of said ring to effect the dislodgment of atapering section of material from the mine roof into and through thecircular opening of said supporting frame to the floor of the minechamber.

19. In mining apparatus, the combination with a circular frame adaptedto rest on the floor of a mine chamber in stationary position, ofkerf-cutting mechanism mounted thereon and extending upwardly therefromon an incline toward the central vertical axis of said circular frame,means for operating said kerf-cutting mechanism including; c1rcular feedthereof relatively to said frame while the latter remains stationary onthe floor of the mine chamber, and means for feeding said cuttingmechanism into the material to produce a connected kerf extending intothe roof of the mine chamber above said frame to surround the inclosedmass to effect dislodgment thereof from the roof.

20. In miningapparatus, the combination with a supporting frame adaptedto rest on the floor of a mine chamber, of a circular ring surroundingsaid frame, kerfcutting mechanism mounted on said ring to traveltherewith circularly, means for ro tating said ring to effect circularfeeding movement of said herf-cutting mechanism while the latter isinclined upwardly from said ring toward. the vertical aXis of theiii-ass to be cut, and means for feeding the kerf-cutting mechanismtoward such axis to gradually increase the depth of the lrerf being cut.

21. In mining apparatus, the combination with a supporting frame adaptedto rest on the floor of a mine chamber, of a supplemental frame mountedthereon for rotary movement relatively thereto, lrerf-cutting mechanismmounted on said supplemental frame to move bodily therewith while occunea position inclined upwardly and towarc the central vertical axis of themass to be cut from the roof of the mine chamber, and means foroperating said kerf-cutting mechanism including rotary movement of saidsupplemental frame to effect the dislodg'ment of a frustum of materialfrom the of the mine chamber.

In mining apparatus, the combination with a supporting frame adapted torest on the floor of a mine chamber and having; a free and unobstructedcircular opening extending verti tally therethrough, of a supplementalframe mounted for circumferential movement on said supporting frame onan upright axis at the center of said circular opening, kerf-cuttiiigmechanism mounted on said supplemental frame for adjustment to aposition inclined upwardly toward such central upright axis and foradjustment to a position inclined downwardly toward such uprlght axis,and means for operating said kerf-cutting mechanism to effect thedislodgment of a frustum of a cone of material from the roof of the minechamber into such unobstructed opening when said kerf-cut ting mechanismis inclined upwardly and to effect the dislodgment of a frustum of acone in the floor of the mine chamber belowsaid unobstructed openingwhen said kerf-cutting mechanism is inclined clownwardly.

23. In mining apparatus, the combination with a supporting frame adaptedto rest in a stationary position on a mine floor, of kerf-cuttingmechanism mounted thereon in position to cut a kerf in the roof of amine chamber above said frame, and means for operating said kerf-cuttingmechanism to cifcct the dislodgment from such roof of a section ofmaterial of a height approximately equal to the height between the floorand roof of the mine chamber and into position between the planes of thefloor and roof while said supporting frame remains stationary.

24-. In mining apparatus, the combination with a supporting frame havingan unobstructed opening extending vertically therethrough for thepassage of a dislodged section of material from the roof of the minechamber, of a plurality of kerf-cutting devices mounted on said framefor bodily movement relatively thereto, means for feeding each of saidcutting devices into the roof longitudinally of the cutting devices, andmeans for feeding said cutting devices laterally along" said frame abouta predetermined mass of material in the roof and around saidunobstructed openings,

In mining apparatus, the combination with a frame adapted to rest in astationary position on the mine floor, of a plurality of kerf-cuttersmovable bodily relatively to said frame, means for feeding saidkerfcutters on an incline toward an upright axis into material abovesaid frame. and means for feeding the cutters laterally to hcrf-cutabout a predetermined mass to enable a tapering section to be dislodgedfrom the space above said fr me.

In mining apparatus, the combination with a main frame, of asupplemental frame mounted on said main frame, kerf cutting mechanismmounted on said supplemental frame, and means for operating said kerfcutting mechanism to effect the dislodgment of tapering section ofmaterial, said main and supplemental frames having openings in theirperipheries adapted to register to enable the dislodged section ofmaterial to be separated from sait frames.

27. In mining apparatus. the combination with a main frame adapted torest in a stationary position on the floor of a mine chamber, of asupplemental frame mounted on said main frame for circumferentialmovement relatively thereto, kerf-cutting mechanisn'r mounted on saidsupplemental frame and movable circumferentially therewith,

' means for moving said supplemental frame on said main frame tofeedsaid cutting mechanism circumferentially, and means for feeding thecutting mechanism upwardly on an incline toward the upright axis ofcircumferential movement of said supplemental frame and into thematerial of the roof of the mine chamber to effect the dislodgment of aconical-shaped section of material from said roof.

28'. In mining apparatus, the combination with a frame, of mechanismmounted thereon for effecting the dislodgment of a mass of material fromits native bed in a mine, to a position surrounded by said frame, andmeans for letting the said dislodged mass down to such position withoutshock or jar.

29. In mining apparatus, the combination with a frame, of a plurality ofdevices mounted on said frame in position for engagin'g a mass ofmaterial partially cut out from its native bed, and means individual toeach of said devices for operating the same to effect dislodgment ofsaid mass of material by alternate operation of said devices. v

80. In mining apparatus, the combination with a supporting frame, ofdevices mounted on said framework and extending toward the centerthereof in position to support a block of material above said deviceswhile said block of material is resting by gravity thereon, and meansfor actuating said devices to engage the block of material and supportthe same as set forth while letting the block move gradually by gravitydownwardly away from the unmined mass.

31. In mining apparatus, the combination with a supporting frame, ofdevices thereon in position to engage the cut section of material in itsnative bed in a mine, and

means for operating'said devices to support such cut section above thesame and while such cut section is in its original or native position,and for letting such section move away from its native positiondownwardly by grz ivity while being supported above said devices.

32. In mining apparatus, the combination with a frame, of supportingmechanism mounted on said frame, and means for swinging said supportingmechanism from a generally horizontal position extending laterally fromsaid frame in position to support a section of mined material, to anupright position free from such section ofmaterial.

In mining apparatus, the combination *v'itli a frame, of spiumia'y ofSupporting ar smeunted en aid ame et spaced Ill-Ell.

apart positions, and means for operating said arms'to-lower a mass ofmaterial from the roof of a mine to the floor thereof.

34L. In mining apparatus, the combination with open framework, of aplurality of supporting devices extending toward the interior of saidframe-work and mounted on the latter in spaced-apart positions, andmeans for operating said devices to support and lower a dislodgedsection of material from its native position in a mine.

3-5. In mining apparatus, the combination with a supporting frame havingan unobstructed opening therethrough for the passage of dislodgedmaterial, of mechanism mounted on said frame for carrying the previouslydislodged mass of material from its native position into said opening ina direction substantially at right angles to the exposed face of saiddislodged mass, and means for operating said carrying means to effectsuch movement of said dislodged mass of material.

36 In mining apparatus, the combination with a supporting frame, of aswinging lever pivoted to said frame to extend laterally therefrom or-to extend transversely thereof, a fluid actuated plunger, a pitmanconnected between said plunger and said lever intermediate the ends ofthe latter, and means for operating and controlling said plunger toactuate said swinging lever into position for engaging material tendingto move transversely of said frame and near the same, and for movingsaid lever-to its transverse position to permit free movement of suchmaterial transversely of said frame and near the same.

87. In mining apparatus, the combination with asupporting frame, of aplurality of devices mounted on said frame in position for engaging theexposed surface of a par-s tially dislodged mass of material in itsnative position in a mine, and means foroperating said devicesindependently of each other to engage such exposed surface of saidpartially dislodged mass and wholly dislodge the same.

38'. In mining apparatus, the combination with a supporting frame, of aplurality of swinging arnis extending toward the interior of said framebut adapted to occupy positions in engagement with a partially dislodgedmass of material in a mine, and means for independently coi'itrollingsaid arms to swing the same to secure complete dislodgment of such massof material.

39. In mining apparatus, the combination with a circular frame, ofswinging devices mounted on said frame in spaced-apart positions andeach directed toward the center L herisental pesitiens: fer supporting ablock of material and to swing said devices to upright positions to letsaid block of material down from its native position.

l0. In mining apparatus, the combination with an arc-shaped frame, of aplurality of pairs of arms mounted on said frame to extend toward thecenter thereof in position to engage a section of mined material andcarry the same, and means for operating said arms by swinging the sameinto substantially horizontal positions for supporting such minedmaterial and by swinging said arms into upright positions to permit themined mass of material to descend by gravity into said frame.

41. In mining apparatus, the combination with a frame, of a pair ofspaced-apart arms, and means for swinging said pair of armssimultaneously against the roof of a mine chamber and simultaneouslydown to an upright position.

l2. In mining apparatus, the combination with a supporting frame havinga free and unobstructed opening therethrough for the passage of a blockof material, of a plurality of pairs of arms mounted on said frame forswinging movement at spaced apart positions into and out of saidopening, and means for operating said pairs of arms to support saidblock of material resting thereon and letting same down by gravity fromits native position into said opening.

43. In mining apparatus, the combination with a circular frame, of aplurality of pairs of spaced-apart arms mounted in spaced apartpositions on said circular frame for swinging movement toward the centerthereof, and means for operating each pair of arms independently ofanother pair to support a block of material in its native position, todislodge the same and carry it away from its native position.

44. In mining apparatus, the combination with a main frame, of asupplemental frame mounted on said main frame for rotary movement,kerfcutting apparatus mounted on said supplemental frame, means foroperating said kerf-cutting apparatus including the feed thereof intothe material, means for rotating said supplemental frame to feed saidlrerf-cutting apparatus in an are, a plurality of independently operatedpairs of arms piv otally mounted on said supplemental frame, means foroperating said arms to engage the section of material while being cut tohold it in place in its native position, and con trolling mechanism tocause said arms to dislodge the said out section and lower the same fromthe roof to the floor of the mine chamber.

4-5. In mining apparatus, the combination with a supporting frameadapted to rest in stationary position on the floor of a mine chamber,of a supplemental.=-frame mounted thereon and confined thereto for apredetermined relative movement, kerf-cutting mechanism mounted on saidsupplemental frame and movable bodily therewith, means for driving saidkerf-cutting mechanism, and means for feeding said cutting mechanismcircularly and conically to effect the dislodgment of a tapering mass ofmaterial from the roof of the mine chamber while said supporting frameremains in stationary position.

@6. In mining apparatus, the combination with a supporting frame adaptedto rest in parallel position in a mine chamber, of a supplemental framemounted on said supporting frame and confined thereto for movement in acircle relatively thereto, cutting mechanism mounted on saidsupplemental frame and movable bodily there with, means for moving saidsupplemental frame in a circle relatively to said main frame to efiectcircular feeding movement of said cutting mechanism, and means forfeeding said cutting mechanism toward the apex of the cone to efiect thecutting of a kerf in the roof above said frame in the shape of a frustumof a cone.

47. In mining apparatus, the combination with a supporting frame adaptedto rest in stationary position on the floor of a mine chamber, ofcutting mechanism mounted on said frame for movement relatively thereto,and means for operating said cutting mechanism to cut into the roofabove said sup porting frame along lines converging toward each otherand surrounding a conical mass of material in said roof.

48. In mining apparatus, the combination with a supporting frame, ofcutting mech anism mounted thereon, means for operat ing said cuttingmechanism to cut a conical kerf surrounding a tapering mass of material,and additional cutting mechanism for effecting a deeper cut near theapeX of such tapering mass of material in the roof of the mine chamberto effect the dislodgment of such tapering mass of material from suchroof.

4:9. In mining apparatus, the combination with an arc-shaped supportingframe adapted to rest in stationary position on the floor of a minechamber, of an additional arcshaped frame mounted on said supportingframe for feeding movement in a circle, cutting mechanism mounted onsaid additional frame, means for feeding said additional frame in acircle together with the cutting mechanism mounted thereon while saidsupporting frame remains in stationary posi tion, and means for feedingthe cutting mechanism toward the apex of a cone having an upright aXisto effect the cutting of a conical kerf surrounding and taperingmass' ofmaterial in its native bed in a mine.

50. In mining apparatus, the combination with an arc-shaped supportingframe adapted to rest on the floor of a mine chamber, of an additionalarc-shaped frame mounted for movement in a circle, cutting mechanismmounted on said additional frame for arcuate movement therewith, meansfor feeding said additional frame together with the cutting mechanismmounted thereon While said supporting frame remains stationary, meansfor feeding the cutting mechanism toward the apex of a cone having anupright axis to cooperate with said arcuate feeding movement to producea conical kerf in the native material in a mine, and additional cuttingmechanism carried by said additional frame for cutting the material nearthe apex of the cone to cause the tapering mass of material to bedislodged by its own weight.

In testimony whereof I have signed my name to this specification, onthis 3d day of July, A. D. 1917.

EDMUND C. MORGAN.

